250TH

Eimac transmitting triode intended for RF power amplification and oscillator service. Published Class-C operating data support hundreds of watts of RF output, with full-input ratings extending into the VHF-range edge.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: MEDIUM4BAYONET
Base pins: 4
Nominal heater: 5 V / 10.5 A

Description

250TH is a Triode device. Radiation-cooled high-power transmitting triode for RF amplifier/oscillator service; 250TH is listed with 250 W maximum plate dissipation. Published operating, rating, and characteristic data from the supplied page were preserved in the technical output.

Socket description

Medium 4-contact bayonet base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: MEDIUM4BAYONET
Base pins: 4
Nominal heater voltage: 5 V
Nominal heater current: 10.5 A
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances

Transconductance: 0.00665 S
Amplification factor: 37
Max plate voltage: 4000 V
Max plate dissipation: 250 W

Published maximum ratings and characteristics audited; additional applicable numerical data retained in parameter table.

Source-dependent data

Operating conditions by source

Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.

Data set 01

1950 Eimac Tubes

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Voltage
5 V
Voltage - 5.0 volts
Current
10.5 A
Current - 10.5 amperes
Grid-Plate [1]
2
Grid-Plate 2 .9 uu f
Grid-Plate [2]
9
Grid-Plate 2 .9 uu f
Grid-Filament
5
Grid-Filament 5.0 uuf
Plate-Filament [1]
0
Plate-Filament - 0 .7 uuf
Plate-Filament [2]
7
Plate-Filament - 0 .7 uuf
Transconductance ( [1]
11
Transconductance (11)=300 ma ., E,,=3000, e(.=-20) 6650 umhos
Transconductance ( [2]
300
Transconductance (11)=300 ma ., E,,=3000, e(.=-20) 6650 umhos
Transconductance ( [3]
3000
Transconductance (11)=300 ma ., E,,=3000, e(.=-20) 6650 umhos
Transconductance ( [4]
-20
Transconductance (11)=300 ma ., E,,=3000, e(.=-20) 6650 umhos
Transconductance ( [5]
6650
Transconductance (11)=300 ma ., E,,=3000, e(.=-20) 6650 umhos
Frequency for Maximum Ratings
40
Frequency for Maximum Ratings 40 me.
D-C Plate Vol tage [1]
1500
D-C Plate Vol tage 1500 2000 3000 3000 volts
D-C Plate Vol tage [2]
2000
D-C Plate Vol tage 1500 2000 3000 3000 volts
D-C Plate Vol tage [3]
3000
D-C Plate Vol tage 1500 2000 3000 3000 volts
D-C Plate Vol tage [4]
3000
D-C Plate Vol tage 1500 2000 3000 3000 volts
Max.-S ignal D-C Plate Cur rent, per tube ':' - • • •
350
Max.-S ignal D-C Plate Cur rent, per tube ':' - • • • 350 mao
Plate Dissipation, per t ube':' • • •
250 W
Plate Dissipation, per t ube':' • • • 250 watts
D-C Grid Vol tage (approx.) a [1]
-30
D-C Grid Vol tage (approx.) a -30 -65 volts
D-C Grid Vol tage (approx.) a [2]
-65
D-C Grid Vol tage (approx.) a -30 -65 volts
Peak A-F Grid Input Voltage [1]
410 V
Peak A-F Grid Input Voltage 410 460 460 volts
Peak A-F Grid Input Voltage [2]
460 V
Peak A-F Grid Input Voltage 410 460 460 volts
Peak A-F Grid Input Voltage [3]
460 V
Peak A-F Grid Input Voltage 410 460 460 volts
Zero-Signal D-C Plate Cu rrent [1]
220
Zero-Signal D-C Plate Cu rrent - 220 14 0 100 mao
Zero-Signal D-C Plate Cu rrent [2]
14
Zero-Signal D-C Plate Cu rrent - 220 14 0 100 mao
Zero-Signal D-C Plate Cu rrent [3]
0
Zero-Signal D-C Plate Cu rrent - 220 14 0 100 mao
Zero-Signal D-C Plate Cu rrent [4]
100
Zero-Signal D-C Plate Cu rrent - 220 14 0 100 mao
Max.-Signal D-C Plate Current [1]
700 mA
Max.-Signal D-C Plate Current - 700 700 560 rna .
Max.-Signal D-C Plate Current [2]
700 mA
Max.-Signal D-C Plate Current - 700 700 560 rna .
Max.-Signal D-C Plate Current [3]
560 mA
Max.-Signal D-C Plate Current - 700 700 560 rna .
Max.-Signal Driving Power Iapprox .) [1]
36 W
Max.-Signal Driving Power Iapprox .) - 36 34 24 watts
Max.-Signal Driving Power Iapprox .) [2]
34 W
Max.-Signal Driving Power Iapprox .) - 36 34 24 watts
Max.-Signal Driving Power Iapprox .) [3]
24 W
Max.-Signal Driving Power Iapprox .) - 36 34 24 watts
Effective Load, Plate-to-Plate [1]
4300
Effective Load, Plate-to-Plate - 4300 6000 12250 ohms
Effective Load, Plate-to-Plate [2]
6000
Effective Load, Plate-to-Plate - 4300 6000 12250 ohms
Effective Load, Plate-to-Plate [3]
12250
Effective Load, Plate-to-Plate - 4300 6000 12250 ohms
Max.-Signal Plate Power Ou tpu t [1]
650 W
Max.-Signal Plate Power Ou tpu t 650 900 1150 watts
Max.-Signal Plate Power Ou tpu t [2]
900 W
Max.-Signal Plate Power Ou tpu t 650 900 1150 watts
Max.-Signal Plate Power Ou tpu t [3]
1150 W
Max.-Signal Plate Power Ou tpu t 650 900 1150 watts
D-C Plate Voltage [1]
2000 V
D-C Plate Voltage 2000 3000 4000 4000 volts
D-C Plate Voltage [2]
3000 V
D-C Plate Voltage 2000 3000 4000 4000 volts
D-C Plate Voltage [3]
4000 V
D-C Plate Voltage 2000 3000 4000 4000 volts
D-C Plate Voltage [4]
4000 V
D-C Plate Voltage 2000 3000 4000 4000 volts
D-C Plate Current [1]
357 mA
D-C Plate Current 357 333 313 350 ma o
D-C Plate Current [2]
333 mA
D-C Plate Current 357 333 313 350 ma o
D-C Plate Current [3]
313 mA
D-C Plate Current 357 333 313 350 ma o
D-C Plate Current [4]
350 mA
D-C Plate Current 357 333 313 350 ma o
D-C Grid Current [1]
94 mA
D-C Grid Current 94 90 93 100 ma o
D-C Grid Current [2]
90 mA
D-C Grid Current 94 90 93 100 ma o
D-C Grid Current [3]
93 mA
D-C Grid Current 94 90 93 100 ma o
D-C Grid Current [4]
100 mA
D-C Grid Current 94 90 93 100 ma o
D-C Grid Voltage [1]
10 V
D-C Grid Voltage - 10 0 - 150 -220 volts
D-C Grid Voltage [2]
0 V
D-C Grid Voltage - 10 0 - 150 -220 volts
D-C Grid Voltage [3]
150 V
D-C Grid Voltage - 10 0 - 150 -220 volts
D-C Grid Voltage [4]
-220 V
D-C Grid Voltage - 10 0 - 150 -220 volts
Plate Power Outpu t [1]
464 W
Plate Power Outpu t - 464 750 1000 watts
Plate Power Outpu t [2]
750 W
Plate Power Outpu t - 464 750 1000 watts
Plate Power Outpu t [3]
1000 W
Plate Power Outpu t - 464 750 1000 watts
Plate Input [1]
714
Plate Input 714 1000 1250 watts
Plate Input [2]
1000
Plate Input 714 1000 1250 watts
Plate Input [3]
1250
Plate Input 714 1000 1250 watts
Plate Dissipation [1]
250 W
Plate Dissipation - 250 250 250 250 watts
Plate Dissipation [2]
250 W
Plate Dissipation - 250 250 250 250 watts
Plate Dissipation [3]
250 W
Plate Dissipation - 250 250 250 250 watts
Plate Dissipation [4]
250 W
Plate Dissipation - 250 250 250 250 watts
Peak R. F. Grid Input Voltage, (approx.) [1]
345 V
Peak R. F. Grid Input Voltage, (approx.) - 345 395 470 volts
Peak R. F. Grid Input Voltage, (approx.) [2]
395 V
Peak R. F. Grid Input Voltage, (approx.) - 345 395 470 volts
Peak R. F. Grid Input Voltage, (approx.) [3]
470 V
Peak R. F. Grid Input Voltage, (approx.) - 345 395 470 volts
Driving Power , (approx .) [1]
29 W
Driving Power , (approx .) 29 32 39 watts
Driving Power , (approx .) [2]
32 W
Driving Power , (approx .) 29 32 39 watts
Driving Power , (approx .) [3]
39 W
Driving Power , (approx .) 29 32 39 watts
':>' ~N"'
-4 A
.':>' ~N"'-4 " CONSTANT CURRENT
the rela tionship of p late efficiency, ~ [1]
35
the rela tionship of p late efficiency, ~ 35 EI M AC 250TH
the rela tionship of p late efficiency, ~ [2]
250
the rela tionship of p late efficiency, ~ 35 EI M AC 250TH
d riving powe r and power output fig
0 W
d riving powe r and power output fig - 0

Data set 02

1958 Amperex Industrial

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Plate voltage
3000 V
RFAmplifierOrOscillator; ClassC; Telegraphy
Plate current
333 mA
RFAmplifierOrOscillator; ClassC; Telegraphy
RF output power
750 W
RFAmplifierOrOscillator; ClassC; Telegraphy
Grid voltage
-220 V
RFAmplifierOrOscillator; ClassC; Telegraphy
Grid current
100 mA
RFAmplifierOrOscillator; ClassC; Telegraphy
Maximum frequency at full input rating
40 MHz

Capacitance

Grid-to-plate capacitance
2.9 pF
Grid-to-filament capacitance
5 pF
Plate-to-filament capacitance
0.7 pF

Data set 03

1962 Eimac

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

Frequency for Maximum Ratings
40 MHz

Other

Maximum DC Plate Current
350 mA

Capacitance

Grid-Plate Capacitance
2.9 pF
Grid-Filament Capacitance
5 pF
Plate-Filament Capacitance
0.7 pF